diff --git a/src/egl/drivers/dri2/egl_dri2.c b/src/egl/drivers/dri2/egl_dri2.c
index daf535178ce..c5fa935657e 100644
--- a/src/egl/drivers/dri2/egl_dri2.c
+++ b/src/egl/drivers/dri2/egl_dri2.c
@@ -2382,6 +2382,18 @@ dri2_query_dma_buf_formats(_EGLDriver *drv, _EGLDisplay *disp,
                                             formats, count))
       return EGL_FALSE;
 
+   if (max > 0) {
+      /* Assert that all of the formats returned are actually fourcc formats.
+       * Some day, if we want the internal interface function to be able to
+       * return the fake fourcc formats defined in dri_interface.h, we'll have
+       * to do something more clever here to pair the list down to just real
+       * fourcc formats so that we don't leak the fake internal ones.
+       */
+      for (int i = 0; i < *count; i++) {
+         assert(dri2_num_fourcc_format_planes(formats[i]) > 0);
+      }
+   }
+
    return EGL_TRUE;
 }
 
@@ -2392,6 +2404,9 @@ dri2_query_dma_buf_modifiers(_EGLDriver *drv, _EGLDisplay *disp, EGLint format,
 {
    struct dri2_egl_display *dri2_dpy = dri2_egl_display(disp);
 
+   if (dri2_num_fourcc_format_planes(format) == 0)
+      return _eglError(EGL_BAD_PARAMETER, "invalid fourcc format");
+
    if (max < 0)
       return _eglError(EGL_BAD_PARAMETER, "invalid value for max count of formats");